Method of and apparatus for treating and testing cores used in coaxial cable units



lNVE/VTORS E. 85/? TAL AN 5. U. R/CE E. BERTALAN ET AL METHOD OF AND APPARATUS FOR TREATING AND TESTING CORES USED IN COAXIAL CABLE UNITS Filed Dec. 6

Jan. 10, 1950 A TTOR/VE Patented Jan. 10, 1950 UNIT ED S TATES OFFICE METHOD OF AND; APPARATUS FOBQTREATE ING AND TESTING? CORESTISED CO- AXIAL CABLE'UNITS Edward Bertalan; Glen Arm, and Edgar U. Rice, Towson, Md assignors. to. Western Electric:- Company, Incorporated; NewYnrk, N. Y., acorporation of Newv York! Application December-'6 194a, SeriarNo. 566;!!10:

which the discs are formed, conductive impurities:

may be applied to the discs by the applying oper ations and conductive impurities maybe gathered by the discs'after they are applied to the central conductors. Some of such impurities cause the.

insulating discs to have an insulating value be low a required minimum value and such. discs.

mustbe removed from central conductors and replaced before the outer conductors can be-apsi plied thereto. Another type of defect of coaxial cables is that of conductive slivers positioned on: the central conductors. when present in a coaxial cable, bridge the gap between the central conductor of the cable and the outer conductor thereof, thereby forming'a low resistance path. between the central and. theouter conductors. However, many such defects, which word is used'hereinafter to designateeither or both slivers and other conductive impurities,

may be. removed by passing a high amperage current through the defects, which current burns away the defects. and makes them less COI'IdllG-- tive, thereby eliminating the necessity of further treatment thereof.

An object of the invention is to provide new: and improved methods of and apparatus for treating and testing articles.

One apparatus for practicing a method em-a bodying the invention comprises means for: ap-

plying a high potential to the outer periphery of a plurality of the insulated discs positioned onacentral conductor to burn out defects therein, means for contacting. the outer peripheries of a plurality ofdiscs which have had a high potential applied thereto by the potential applying means, and means associated with the contact-. ing means for indicating the presence of a defect which has not been burnedaway.

' A complete understanding-of the invention-may- Some of such slivers;

2. be obtainedafrom the, tollowing detailed. description of an, apparatus; forming: a specific embodimerit thereof, when read in conjunction with the appendedadrawings, ilr'whichz;

Fig. 1 is a; partially diagrammatic, partially sectionalg-View of anapparatus embodying the (polymerized ethylene).

invention; and:

Fig=,2, isan-enlarged. perspective view of a portionof'the apparatus."

Refe'rringrnow indetailto the drawings, a filamentary conductorl-DpzQFlgl 1); is drawn through a..disc applicator liagof suitable construction, which applies" insulatingzdiscs l-Z-l 2, which haveslits f3+-l3 thereim. upon the conductor II) at regularly spaced intervals, whereby a core. I1 is formed. The discs-.1 2;-+'-l2.ar.e formed of an elec trical insulating;materiabsuch. as a rubberor av rubber-like compound; or other suitable electrical: insulating materials; such as polyethylene After the discs have been applied, the core; is advanced through a burnoutzelectrode: 1.4 a: detecting electrode l5, a-tubeformer 20xof suitable design, which applies an: outer tubular; conductor 2| over-the discs, and

a taping head 22',- which applies a tape 23: over the-outer. conductor 21h to form av coaxial cable unit 25. The'coaxial: cable unit: passes around a capstan, whichlserves-to advance the elements ofithe coaxial cable unit-through the elements of theapparatusv justv described atxa constant rate of speed;

The, burnout electrode. 14" (Fig.- 2). includes a stationary plate 30:1havinga-groove 3| formed therein,:.which is .fla'red at the endsthereof. The

"plate.30.rests-upon,;suppQrts: 32-32 formed of aninsulating; material and has a plurality of bolts 33i--33;projecting-:from.the upper surface thereof. The bolts senvetoi mount avplate 34 on the plate.

30; in such. a: mannenthattthe plate 34 may be" moved freely towardzor away from the plate 30.

Thepl'atefiflis provided with a groove 35, which is complementary tame: groove 3 li and is flared at theendsthereof; When: the core unit I] is advancedythrough. the grooves: .31 and 35, the plates 30' and: 34. contact substantially the entire peripheriesof: the-discsz,-l2;1- 2; and the plate 34 rests upon the discs;v

A conductor. 10, (Fig; 1;). connects the: electrode Mtoa tap M; paz econdar winding 42" of a high potential; .tmnsrcemeesa; while conductors 44 taps 5655 to which the conductor 45 may be secured to vary the output potential of the trans-.

former 43. The secondary winding 42 has, in

addition to the taps M and 55, a tap 51, which 1' connects a conductor T4 to the secondary winding, and taps 58-58. The conductors 40, 54 and 14 may be connected to others of the taps of the secondary winding to obtain diiTerent potential is lighted, it indicates to an operator of the apparatus that the detecting electrode I5 has contacted a defect in the core H which was not de stroyed by the burnout electrode I4.

The relay 96 includes a contactor IIO, which is normally in engagement with a contact I I I. When the relay 96 is operated, the contactor 93 is moved into engagement with the contact 94, the engagement between contactor H0 and the contact HI is broken and a latching armature II2 of a relay II3 latches the contactors 93 and H0 in such positions. The contact I II is connected by a conductor II4 to a motor controller I I5 of standard construction, and a conductor I connects the contactor IIO to a contact I2I ,f-of a relay I22.

difierences therefrom.

When the transformer 43 isenergized, a big potential is applied to the burnout electrode I4, and if defects of a type which may be burned away are present in the portion of the core passing through the burnout electrode, current will flow through such defects from the burnout electrode I4 to the grounded conductor I0 and the defects will be burned aways The transformer 43 is designed to apply a potential as high as 4000 or more volts to the electrode I4. Consequently, any defects susceptible of being burned away by such a potential are destroyed.

The detecting electrode I5 is identical in construction with the burnout electrode I4 and includes a stationary plate 63 having a groove 64 provided therein and a movable plate 65 having a groove I0 formed therein. serves to connect the electrode I5 to a winding 12 of a high-sensitivityrelay I3, and the winding I2 is connected by the conductor I4 tothe tap 51 of the secondary winding 42 of the transformer 43.

When the transformer 43 is energized, a high potential is applied to the electrode I 5. However, this potential is not so high as the potential applied to the burnout electrode I4 since the tap 51 is at a lower potential then the tap 4|. The potential applied to the'detecting electrode I5 is high enough to cause current to pass through a portion of the core I! having a defect therein, but is low enough that no current flows through satisfactory portions of the core.

When a portion of the core I! having a defect therein which has not been burned away is advanced through the detectingelect'rode I5, current flows from the electrode I5 through the defect and the conductor I0. This causes current to flow through the winding I2 of the relay I3, whereby a contactor 82 of the relay is drawn into engagement with a contact 83. A conductor 84 connects the contactor B2 to the conductor 44 of the power line 50, and a conductor 85 connects the contact 83 to a winding 90 of a relay 96. A conductor 9I connects thewinding 90 to a conductor 92 connected to the conductor of the power line. Thus, when the contactor 82 is in engagement with the contact 83, the winding 90 is supplied with current from the power line 50, whereby the relay 96 is energized and causes a contactor 93 to be drawn into engagement with a contact 94 of the relay 96. When the relay 96 is actuated and the contactor 93 is in engagement with the contact 94, a lamp I03 is lighted by current passing thereto through conductors 44, I05 and I04, and through conductors 45 92, 9|, I00 and 95, the contactor 93, "the contact 94 and a conductor I02. When the incandescent lamp'l03.

A conductor 'II i A winding I23 of the relay I22 is connected by a conductor 24 to the conductor 92 and by a conductor I25. to the conductor 44 so that, when ever the switch 56 is closed, the winding I23 will be energized, whereby a contactor I30 of the relay I22 is held in engagement with the contact I2I. Whenever the switch 55 is open, the winding I23 is ole-energized and the engagement between the contact I2I and the contactor I30 is broken. The contactor I30 is connected by a conductor I3I to the motor controller H5, and, whenever the engagement between the contactor I30 and the contact I2I is broken, the motor controller H5 cannot be actuated and the driving motor (not shown) controlled thereby cannot be operated, whereby the capstan 24, the taping head 22, the tube former 20 and the disc applicator II, all of which are driven by the driving motor, will not be driven.

The relay II3 includes a winding I32, which is connected to the conductor I00 by a conductor I33, and is connected by a conductor I34 to a contact I35 of a manually operable, reset switch I40. The switch I40 includes a contactor MI and a contact I42, which is connected. by a con ductor I43 to the conductor I05. Thus, when the switch I40 is closed, the winding I32 is energized.

In the operation of the apparatus described hereinabove, an operator closes the switch 56, whereby high potentials are applied to the electrodes I4 and I5 and the relay I22 is operated to cause engagement between the contactor I30 and the contact i2 I, which closes a control circuit to the motor controller II5. Since this circuit is closed the motor controller II5 can be actuated to start the driving motor (not shown), which is done, and the driving motor drives the capstan 24, the taping head '22, the tube former 20 and the disc applicator II.

The capstan 24 then advances the central conductor I0 through the disc applicator II, which applies the discs I2-I2 to the central conductor at spaced points thereon, and the grounding electrode 62 grounds the central conductor as the central conductor is advanced to the disc applicator. The core I! consisting of the central conductor I0 and the discs I2I2 thereon then is drawn through the burnout electrode I4, where the peripheries of the discs I2 I2 are closely contacted by the plates 30 and 34. If defects are present in the portion of the core in the burnout electrode, current is passed through the defects, which, if they are susceptible of being burned away by the high current, will be burned away as the defective portion of the core I! is advanced through the electrode I4.

The core I! then is drawn through the detecting electrode I5, which is at a potential somewhat lower than that of the burnout electrode I4. If

enemasthe portion-cfi-thecore passing through the de-q tecting electrode I 5 hascan insulating ;value. abovea predeterminedvalueaand :no defects. are present therein, -no; currentflowsiromgthe electrode I 5. to

the grounded, conductor l0.w Howeverrif any-aundestroyed defects are.- present 'inthe portion of the core in the detecting :electrode and :f orm apath of lowresistancewin that aportiom current, flows from the electrode I 5-tthrough the detectto the ,grounded, conductor I and a the. ghigh-sensi-i tivity relay 1 l 3, is: operated, whereby the :contactora 82- and vthe contact-83am brought into engage:- ment-and the relay ilfi (Fig. 1) isoperateda When the relay 9B-is operated, the contactor 8.3:

is brought into engagement 'withlthe contact '94. the engagement between, the-,contactor, I Iii-and the contact III is broken and the-latch I I2 latches the, contactor 93-vandl ID in such positions.

When the eneager-nent between; the con-tactor 1 I and .the-contact III- is broken, the circuit to the: motor controller II5 isabroken; whichlcauses the driving i motor (not; shown); to; be. rile-energized;w

whereby the operations of; :the capstan 24;- the tapingchead 22rthe tube former and the-discapplicator II are stopped.-

Whenthe contactorSB is-broug-htinto engage mentwith thexcontact 94, the incandescentlamp. IDS is lighted, which indicates to anioperator of the apparatusthatathe detecting-electrode I5:has; contacted a defect. The switch 56 then is opened and the defect isremovedfrom the core IT.

The re-start'the apparatus after the defect: has: been removed; I the switch "5 64 I isuclosed, whereby the winding I23,of'the relay I 2 2 .isenergized, the contactor I is broughtinto engagernent with; the contact I2I andtheelectrodes I4 and 'l5-are energized. However,- the-;-motor controller I I5 cannot be actuated to startthe motoratthistime because the latching armature -I I 2 holdsthe contactor 'I I0 outrof engagement with the vcontact I l I and the circuit to the motor-l controlleris open; The latching armature ,I I2 then is caused a to, re-.- lease the, contactors 93 and :l-Hlby operatingnthe, reset switch I s After the winding I32 oftherelay-Il3 draws the latchingarmature I I 2 I out of.- engagement- Withthe contactor: H0,- if the zportion. of. thecore"; l I! contactedlby the detecting electrode I 5 is'free from defects-the contactor HGf-mOVBS-iHtO EH:-

gagement Withthe. contact III andthecontactor 93moves out of engagement with the contact 94". The breakingof-theengagementbetween the, contactor 93 and the:contact -Btbrealzs =the-circuit to the lamp I03 Which1isa'darkened, thereby indicating-that the portion of-thecore contacted by the electrode I5 has no defectsandithat the; motor controller I 15 maybe actuatedto; start the apparatus, The switch I40 then, is opened whereby thewinding. I32,of; the relayd I3 is de-= energized, andthe motor controlleris actuated'to start the driving motor toestart the operationlof; the apparatus.

The burnout-electrode I 4 .destroysma-ny defects, of the core H 50. that the apparatusheed notbe stopped torepair. the -defective,- portions; ofthescore, andthe testing electrode-I .5 detectsany urnv destroyed defects of. 1 the care i before the-.-outer.= conductor is applied :thereoven- As a-,result,--while most defects are. burned: awayby; theeburnout electrode, any defects which cannot be burned away are locatedby the testingelectrode. If desired, one or. more additional testing electrodes may be inserted intoethe apparatus, together with: circuits similar to the above: described circuit; for further testing operationsc 6. Whatds; claimed rise; 1; An apparatussforstestinarawcontinuously: ade vancing icoreof a; coaxial loable, Zunithaving insu-v lating discs spacedly positioned along a filamem.

tary ,central conductor, which, compri e D111- ral-ity. of electrodes spacedly positioned, along the. path of. travel of the core and. adapted. tosuccessively engage thesperipheries of the 7 discs as the core ;pass esl through the said electrodes,

-means.-,-for: continuouslyapplying, an electrical potentialacnoss the central conductor of the core and-atleast the-first of saidelectrodeshaving an intensity suflicientitoncausea current toiflow through and burn; away defects providing. paths.

o. of ;-reduced dielectric:- strengthbetween the electrode and thetcentraltconductor in the portionof,

thecore advancing .therethrough, and means for,

continuously -v applying: an electrical potential across thenremaining electrodes ;and the central.

conductor; havineanzintensit sufiicient to cause,v acurrent to floweacross any. defects in the portion of thetcore passing-therethrough which a were not burned away .by; thenfirst; mentioned electrode, whereby an o defects encountered'by the last men.-

-,. tionedelectrodes may be, detected.

mentary centralconductor, which comprises an.

electrode hayingr a bore'adaptedtocn h peripheries of a.-p1urality-ofv thediscs asthe core advances therethrough, a second electrode ehav ing a-bore adapted to engage the peripheries of apluralityofthe discs assthe core passes therethrough uponemerging fromqthe firstimentioned electrode, means for continuously applying I an, electrical potential across the central conductor,-

and the. first mentioned electrode having, an intensitysuflicient. to. .cause a current tov flow.

throughandburn. away defects which provide pathslof reduceddielectric strengthibetween the electrode and) the central. conductor in the pertionlrof the .core passing through said electrode. and means. for, continuously applying an electricalipotential;acr0SSr-.the,sec0nd electrode and the central conductor having an intensity. suflicient to.

cause a current, torflowthrloughany; defects in they portion of the .core passing. therethrough which werenot burnedcaway by thefirst mentioned,

electrode,,.whereby any defects encountered by the zsecondlelectrode maybe detected.

....sufiicient- .to; burnawayzvdefectsa Which:- provide paths on ,recluced-cdlelectricx strength; between the;

electrode and the central conductor in the pore: tion ofrthe; core.ipass'in vsthrough; said electrod meansafor; continue.11 1s!-v pp i ez n; electrical potential acrossythesecond. electrode and. the central conductor ofu-thefcore'having-ran intensity sufiicient tmcausezacufient to flow through any deiectfizeinrthercpoltiqnaof the :core unit: passing; therethrouehnwhichzwerev not .burnedzaw y y" -thee firstreleetrcda andhmeanseelectricallyeasses ciated with the second electrode for indicating when current is flowing through a defect in the portion of the core encountered by the second electrode.

l. An apparatus for testing a core of a coaxial cable unit having insulating discs spacedly positioned along a filamentary central conductor, which comprises means for continuously advancing such a core along a predetermined path, an elongated electrode adapted to engage the periphery of a plurality of discs of the core advanced by the advancing means, asecond electrode! adapted to engage the periphery of a plurality of the discs of the core after the core unit emerges from the first electrode, a transformer energizable to continuously impress across the first mentioned electrode and the central conductor of the core unit an electrical potential having an intensity suflicient to cause a current to flow through and burn away defects providing paths of reduced dielectric strength between the electrode and the central conductor in the portion of the core passing therethrough, said transformer being arranged to continuously impress across the second electrode and the central concluctor of the core an electrical potential having an intensit sufficient to cause only a current to flow through defects in the portion of the ,core passing therethrough which were not burned away by the first mentioned electrode, an electric circuit for selectively controlling the operation of the advancing means, and means electrically associated with the second electrode for causing the control circuit to stop the advancing means when a defect which was not burned away by the first electrode is encountered by the second electrode.

5. An apparatus for testing a continuously advancing core of a coaxial cable unit having insulating discs spacedlypositioned along, a filamentary central conductor, which comprises means for continuously advancing a core having insulating discs spacedly positioned thereon along a predetermined path of travel, means for substantially enclosing successive portions of the advancing core, a second means for enclosing successive portions of the advancing core after it leaves the first enclosing means, means for continuously applying across the first enclosing means and the central conductor of the advancing core a potential having intensity sufiicient to cause a current to flow through defects providing paths of reduced dielectric strength in portions of the core encountered by the first enclosing means suificient to burn away such defects, said potential applying means being arranged to simultaneously apply across the second core enclosing means and the central conductor of the advancing core a potential having an intensity sufficient to cause a current to flow through defects which were not burned away as the core advanced through the first core en'- closing means which will not burn away the defects, and means associated with the second enclosing means for indicating when said defects are encountered by the second core enclosing means.

6. The method of testing a continuously advancing core of a coaxial cable unit having insulating discs spacedly positioned along a filamentary central conductor, which comprises passing such a core continuously through an elongated electrode adapted to engage'the discs of the conductor of the advancing core, constantlyjapplying a potential across the electrode and the central conductor of the core having an intensity sufiicient to cause a current to flow through and burn away any defects providing paths of reduced dielectric strength in the portion of the core passing through said electrode, passing said core continuously and directly from said electrode through a second electrode, constantly applying a potential across the central conductor and the second electrode suflicient to cause a current flow through any defects in the portion of the core passing therethrough which were not burned away as the core passed through the first mentioned electrode, and utilizing the current flowing through defects encountered by said sec ond electrode to indicate the presence of such defects in the advancing core.

7. The method of testing a core of a coaxial cable unit having insulating discs spacedly positioned along a filamentary central conductor, which comprises passing such a core continuously through an elongated burn-out zone adapted to surround the discs of the advancing core, creating a potential difference between the burnout zone and the central conductor of the core of such intensity as to cause a current to flow through and burn away defects providing paths of reduced dielectric strength in the portion of the core unit passing through said burn-out zone, passing said core from said burn-out zone through a testing zone adapted to surround the discs of the advancing core, creating a lower po tential difference between the central conductor and the testing zone of such intensity as to cause only a current flow through defects in the portion of the core passing therethrough which were not burned away as the core passed through the burn-out zone, and utilizing the current flowing through defects encountered by the testing zone for stopping the advancement of the core.

8. The method of testing a continuously advancing core of a coaxial cable unit having insulated discs spacedly positioned along the filamentary central conductor, which comprises advancing a core along the predetermined path of travel, grounding the central conductor of the core, continuously applying a potential around the periphery of each of the insulating discs of the advancing core to cause a current to flow through any defects providing paths of reduced dielectric strength between the periphery of the discs of the central conductor sufiicient to burn away such defects, and subsequently applying a potential around the periphery of each of the discs of the advancing core to cause a current to flow through defects which were not burned away by the prior application of potential, whereby the defects which were not burned away by the first application of the potential may be detected by the application of said second potential.

9. The method of testing a continuously advancing core of a coaxial cable unit having insulating discs spacedly positioned along a filamentary central conductor, which comprises continuously advancing a core having discs positioned thereon along a predetermined path of travel, continuously creating a potential difierence between the periphery of the insulating discs and the central conductor of successive portions of the advancing core having an intensity sufiicient to cause a current to flow through any defects providing paths of reduced dielectric strength between the periphery of the discs and the central conductor that will burn away such defects, continuously creating a potential dinerence between the periphery of the discs and the :entral conductor of successive portions of the REFERENCES CITED advancing core having an intensity sufficient to The fouo eferences f 0rd h :auseacurrent to flow through any defects which file of fggf f e 0 me 1 t e were not burned away by the prior application )f potential which will not burn away such de- 5 UNITED STATES PATENTS fects, and utilizing the current flowing through Number Name Date the defects as a result of the second application 920,970 Mansbridge May 11, 1909 of the potential to indicate the presence of de- 1,782,403 Bouvier Nov. 25, 1930 Eects in the core which were not burned away by 2,043,528 Davis June 9, 1936 said first potential difference. 10 2,060,162 Boe Nov. 10, 1936 2,087,783 Savage July 20, 1937 EDWARD BERTALAN. 2,099,112 Hill Nov. 16, 1937 EDGAR U. RICE- 2,108,6 37 Bartgis Feb. 15, 1938 

